1. Field of the Invention
The invention relates in general to laundry detergent compositions and in particular to such compositions in the form of a translucent, stable, viscous, single phase gel readily dispensible in aqueous media over a wide temperature range.
2. Description of the Prior Art
Liquid laundry detergents heretofore provided and containing appreciable amounts of phosphate builder invariably require significant amounts of coupling or emulsifying agents to produce stable, single phase systems. For example, it is the usual practice to utilize hydrotropes such as lower alkyl aryl sulfonates e.g., sodium toluene sulfonate and the like with anionic type detergents, while resinous polymers such as polyvinyl methyl ether-maleic anhydride (PVM/MA) are similarly used with nonionic type detergents. Even with the use of such stabilizing agents, the amount of phosphate builder tolerated by the detergent composition is nevertheless limited to amounts on the order of 15 to 25% by weight of total composition. The use of such coupling or emulsifying agents as stabilizers can be burdensome both from a formulations standpoint and an economic standpoint. Thus, the normally inherent advantage of the liquid type detergent as regards ease of water dispersibility, particularly in cold water, vis-a-vis powdered or particulate detergents is somewhat offset by the limitations imposed on phosphate loading. Thus, increasing the phosphate content of liquid detergents substantially in excess of about 25% by weight invariably leads to phase separation and consequently, a product having little customer appeal.
Powdered detergents, though tolerating larger quantities of phosphate, suffer by comparison with liquid detergents with respect to water dispersibility. This is a particularly important consideration with respect to cold water washing.
A further disadvantage of the currently available powdered or liquid detergents is their limited effectiveness for use with washing machines provided with foraminous or open bucket type dispensers, this type of washing apparatus being particularly popular in European countries. With this type of washing machine, foraminous or open type buckets are attached to or integral with the machine and are positioned to communicate with the washing medium. The machine is equipped with suitable means enabling the programmed, incremental or delayed introduction of the contents of the buckets into the washing medium as by tipping, flooding, etc. In this manner, detergent, bleach, softener and the like are added to the washing medium automatically according to a predetermined schedule impressed upon the machine by the operator. Thus, liquid detergents often prematurely spill into the washing medium in significant amounts which may be due to the turbulence created by machine vibration while powdered detergents are apt to become clogged or caked due to the surrounding moist environment and thus difficult to discharge completely and efficiently from the bucket type container.
It is thus a primary object of the invention to provide detergent composition in stable gel form wherein the foregoing and related disadvantages are eliminated or at least mitigated to a substantial extent.
Another object of the invention is to provide detergent compositions in gel form capable of tolerating significant quantities of phosphate builder.
Still another object of the invention is to provide detergent compositions in gel form forming translucent, stable, single phase compositions having little or no tendency to "bleed" or otherwise phase separate despite prolonged periods of standing.
Yet another object of the invention is to provide gel type detergent compositions advantageously adapted for use with washing apparatus equipped with foraminous or open type bucket dispensers.
A further object of the invention is to provide gel type detergent composition wherein any necessity for use of coupling or emulsifying agents such as hydrotropes and organic polymeric resinous materials is eliminated.
A still further object of the invention is to provide a gel type detergent composition readily dispersible in aqueous media over a wide range of temperature having excellent detergency and especially with respect to particulate soil stains.
Yet a further object of the invention is to provide a gel type detergent composition which is essentially self supporting and may be readily and conveniently dispensed from a variety of carriers such as a tube, with practically no problem of spillage.
Other objects and advantages of the invention will become apparent hereinafter as the description proceeds.